Matching stripes
My tip solves the problem of matching stripes on T-shirt knit at the side seams, since you can't pin them and sew right up to the pins, like we do w/ the sewing machine. I use a water-soluble glue stick to "baste" the seams together, then just serge. Of course, you will have to wash the shirt when you're finished w/ it. But it's worth it to get the match right. This is a glue stick, that twists up like a lipstick, not your hot glue gun. You can buy them at office supply stores, stationary depts of chain stores and some sewing stores.
I also just read in book last night to put bottom layer every so slightly out from top and you can see the stripes, no pins, no glue.